1. Field
One or more embodiments of the present invention relate to a probe member for a pogo pin, and more particularly, to a probe member for a pogo pin that reliably contacts a terminal of a semiconductor device so as to be electrically connected well.
2. Description of the Related Art
Generally, in order to test electrical characteristics of semiconductor devices, a semiconductor device needs to have a stable electrical connection with a test device. Generally, a test socket is used as a device for the connection between the semiconductor device and the test device.
The test socket connects a terminal of the semiconductor device and a pad of the test device so that electrical signals may be exchanged bidirectionally. To this end, a pogo pin is used as a contacting unit in the test socket. The pogo pin includes a spring to easily connect the semiconductor device and the test device and to absorb a mechanical shock which may occur during the connection, and thus, it is used in most test sockets.
FIG. 1 schematically illustrates a general pogo pin.
A semiconductor device 1 that is a tested device includes an external connection terminal 2, and a test substrate 8 including a substrate pad 9 is disposed to correspond to the external connection terminal 2. In addition, a pogo pin 3 is located between the semiconductor device 1 and the test substrate 8 to electrically connect the semiconductor device 1 and the test substrate 8 to each other. In FIG. 1, a body of the test socket is omitted. As shown in FIG. 1, the pogo pin 3 includes an upper plunger 5 and a lower plunger 6 on opposite ends of a body 4, and a spring 7 is inserted into the body 4. Accordingly, the spring 7 applies an elastic force to the upper plunger 5 and the lower plunger 6 in a direction in which the upper and lower plungers 5 and 6 are apart from each other. Here, the upper plunger 5 is connected to the external connection terminal 2 of the semiconductor device 1, and the lower plunger 6 is connected to the substrate pad 9 of the test substrate 8. Accordingly, the external connection terminal 2 and the substrate pad 9 are electrically connected to each other. That is, when an end of the upper plunger 5 contacts the external connection terminal 2 of the semiconductor device 1 and an end of the lower plunger 6 contacts the substrate pad 9 of the test substrate 8, the external connection terminal 2 and the substrate pad 9 are electrically connected to each other.
Another conventional pogo pin is disclosed in Korean Patent Application No. 10-2011-0127010. In particular, FIGS. 2 and 3 illustrate a pogo pin for semiconductor testing that electrically connects a semiconductor device (not shown) to a test substrate (not shown) to test the semiconductor. The pogo pin includes a first plunger 20, a second plunger 30, and an elastic member 40. A movement space penetrated on two sides is formed in the first plunger 20. The second plunger 30 is formed of a conductive material. Also, the second plunger 30 is inserted into the movement space of the first plunger 20 so that an end of the second plunger 30 selectively protrudes over a contact exit 22′ on a side of the movement space. The elastic member 40 is inserted between the first plunger 20 and the second plunger 30 to apply an elastic force in a direction in which the first plunger 20 and the second plunger 30 are apart from each other. An end of the second plunger 30 is connected to a substrate pad of the test substrate and the other end of the second plunger 30 is exposed outwards from the contact exit formed on one side of the movement space of the first plunger 20 by a relative movement of the first plunger 20 and the second plunger 30, to be connected to an external connection terminal of the semiconductor device.
The above-described pogo pins have the following problems.
Generally, the semiconductor device contacts the pogo pin by descending in a state in which the semiconductor device is inserted into a receiving socket. However, it is difficult for the terminal of the semiconductor device to be located at the center of the pogo pin, as the insert descends. In particular, recently, terminals of the semiconductor device tend to have small sizes and narrow distances among one another, and thus, it has become even more difficult for the center of the terminal of the semiconductor device to form an identical axis with the center of the pogo pin, as the semiconductor device descends.
If the terminal 2 of the semiconductor device 1 does not descend by forming an identical axis with the center of the first plunger 20 and descends while being deviated from the center of the first plunger 20 by a predetermined distance P in a horizontal direction, as shown in FIG. 4, the terminal 2 of the semiconductor device 1 may not reliably contact probe portions of the first plunger 20, as shown in FIG. 5. That is, even when the terminal 2 contacts the probe portions, the terminal 2 may not contact a plurality of probes and may contact only a portion of probes so that the contact performance is largely deteriorated.
When the contact between the pogo pin and the terminal of the semiconductor device is not solid, the reliability of a test result of the semiconductor device may become decreased.